Timber Management: Aerial Broadcast for Woody Control
The application of a broadcast herbicide for the control of woody brush species is often advisable on cutover
and semi-open tracts of land. Hardwoods often establish
themselves within a pine stand even when initial steps to
remove them occurred before planting. Hardwood sprouts
will compete with young pines for moisture and sunlight
and inhibit pine growth and survival.
Sometimes called “Pine Release”, this management practice
is usually conducted during the late summer or early fall
of the year after planting has occurred. Because most herbicides used for release are foliar active (absorbed through
the leaves), it is best to spray before the hardwoods lose
their leaves for the winter. Best results are obtained when
the application is made from August to October. During this time, the translocation of food reserves from the
leaves to the root is occurring and potential injury to pine
seedlings is minimized because pine seedlings are forming their final resting buds. Application of the chemical
is most often conducted from the air, using a helicopter
equipped with a boom-type spray assembly.
Herbicide Selection:
Herbicides are site specific and each herbicide is best suited for a particular purpose on a given site. Factors influencing suitability include: the type of vegetation to be controlled, the species and age of the trees to be over-sprayed,
soil type, time of year, proximity to streams, sensitivity of
surrounding areas to damage from herbicides and cost.
Common herbicides for the control of woody vegetation
include various formulations of the chemicals imazapyr,
glyphosphate, and triclopyr amine or ester. These chemicals act to inhibit enzyme production and/or regulate
growth in hardwood species. In order to facilitate adherence to the leaf surfaces of plants, these herbicides are often combined with a surfactant. It is a violation of Federal
http://tfsweb.tamu.edu
Law to use these products in a manner inconsistent with
their labeling (see specimen labels for use, precautionary
statements, mixing, handling, application and disposal instructions, etc.). For the proper herbicide mix for a site,
consult with a pesticide applicator certified by the State
of Texas and remember that all applicable Texas Forestry
Best Management Practices for Silvicultural Chemicals
should be followed. For more information, please visit http://tfsweb.tamu.edu/BMP or contact your local Texas
A&M Forest Service office.
Benefits:
Chemical release operations remove unwanted vegetation
in competition with young pines. Reducing the amount
of hardwood competition present on the site will help
to increase the survival and growth of pine seedlings by
making moisture, nutrients, and light, which would have
otherwise been used by the hardwoods, available to the
pine seedlings. Application of woody release is especially
important to the survival of young pines during droughty
periods, when seedlings are already stressed.
Additional Information:
For more information on forestry herbicides, including
application rates, targeted species, and material safety data
sheets consult the online CDMS herbicide database on the
Internet. The database has label and safe handling information for all major forestry herbicides. The CDMS web
address is: http://www.cdms.net/LabelsMsds/LMDefault.
aspx
Page 1 of 1